Resin molded type semiconductor device and a method of manufacturing the same

ABSTRACT

A resin molded type semiconductor device has: a semiconductor chip ( 12 ) which is mounted on a die pad portion ( 11 ) of a lead frame ( 9 ); thin metal wires ( 14 ) which connect terminals of the semiconductor chip ( 12 ) to inner lead portions ( 13 ) of the lead frame ( 9 ); and a sealing resin ( 15 ), and the lead frame ( 9 ) is subjected to an upsetting process so that a supporting portion ( 11 ) is located at a position higher than the inner lead portions ( 13 ). Since the sealing resin of a thickness corresponding to the step difference of the upsetting exists below the supporting portion, the adhesiveness between the lead frame and the sealing resin can be improved, and high reliability and thinning are realized. Since at least one groove portion is disposed in the surface of each of the inner lead portions ( 13 ), the anchoring effect to the sealing resin ( 15 ), stress acting on a lead portion of a product, and stress to the thin metal wires ( 14 ) can be relaxed, and leads and the thin metal wires can be prevented from peeling off.

This is a divisional application of U.S. application Ser. No. 09/380,312filed Aug. 31, 1999 which is a 371 of PCT/JP98/02544 Jun. 8, 1998.

TECHNICAL FIELD

The invention relates to a resin molded type semiconductor device inwhich a semiconductor chip is mounted on a lead frame and the outerperiphery of the semiconductor chip, particularly, the upper face of thesemiconductor chip is molded by a sealing resin, and also to a method ofmanufacturing the semiconductor device.

BACKGROUND ART

Recently, as the density of board mounting advances, semiconductorproducts which are to be mounted on a board are requested to beminiaturized and thinned. In order to realize miniaturization andthinning, the TAB mounting technique using a resin tape has beendeveloped. In a development of a thin semiconductor product using a leadframe, a resin molded type semiconductor device of the single-sidemolding type in which a semiconductor chip is mounted on a lead frameand the mounting face is molded by a sealing resin has been developed.

Hereinafter, a resin molded type semiconductor device of the prior artwill be described. FIG. 5 is a section view showing a resin molded typesemiconductor device of the prior art.

In the resin molded type semiconductor device of the prior art shown inFIG. 5, a semiconductor chip 3 is mounted on a die pad portion 2 of alead frame 1, and terminals (not shown) of the semiconductor chip 3 areelectrically connected to inner lead portions 4 of the lead frame 1 bythin metal wires 5. In a single face of the lead frame 1, i.e., the faceof the lead frame 1 on which the semiconductor chip 3 is mounted, theouter peripheral region of the semiconductor chip 3 is molded by asealing resin 6.

In a resin molded type semiconductor device produced so as to have astructure such as shown in FIG. 5 is provided with a structure in whichan outer lead portion 7 serving as external terminals is arranged on abottom face of the semiconductor device. Since only the face of the leadframe 1 on which the semiconductor chip 3 is mounted is molded by thesealing resin 6 and the rear face of the lead frame 1 is notsubstantially molded, it is possible to realize a thin resin molded typesemiconductor device.

Next, in a method of manufacturing the resin molded type semiconductordevice of the prior art shown in FIG. 5, a tapered shape is first formedat tip end portions of the inner lead portions 4 of the lead frame 1 bymechanical or chemical working, and the semiconductor chip 3 is thenbonded onto the lead frame 1. Thereafter, the semiconductor chip 3 iselectrically connected to the inner lead portions 4 of the lead frame 1by the thin metal wires 5, and the face of the lead frame 1 for mountingthe semiconductor chip 3 is then molded by the sealing resin 6 by meansof transfer molding. In order to form external terminals, finally, theouter lead portion 7 of the lead frame 1 which projects from the sealingresin 6 is worked, thereby completing the resin molded typesemiconductor device.

In the prior art, in addition to a resin molded type semiconductordevice of the structure shown in FIG. 5, also a structure shown in FIG.6 is employed.

In the resin molded type semiconductor device shown in FIG. 6, aninsulative resin tape 8 on which a semiconductor chip 3 is to be mountedis bonded to tip end portions 4 a of inner lead portions 4 of a leadframe 1, thereby forming a die pad portion. The device has a structurein which, after the semiconductor chip 3 is mounted on the resin tape 8,terminals of the semiconductor chip 3 are electrically connected to theinner lead portions 4 by thin metal wires 5, and the face of the leadframe 1 for mounting the semiconductor chip 3 is molded by a sealingresin 6. The resin molded type semiconductor device shown in FIG. 6 hasthe merit that the device can be made thinner than the resin molded typesemiconductor device shown in FIG. 5. Specifically, in the resin moldedtype semiconductor device shown in FIG. 6, the resin tape 8 is bonded tothe lower faces of the inner lead portions 4 of the lead frame 1 and thesemiconductor chip 3 is mounted on the upper face of the portion.Therefore, the step difference between the upper faces of the inner leadportions 4 and the upper face of the semiconductor chip 3 is reduced. Asa result, also the resin thickness of the sealing resin 6 is reduced,and the resulting resin molded type semiconductor device has a reducedthickness. In the resin molded type semiconductor device shown in FIG.5, since the semiconductor chip 3 is mounted on the die pad portion 2which is in the same level as the inner lead portions 4, the thicknessof the sealing resin 6 cannot be reduced by such a degree that isattained in the resin molded type semiconductor device shown in FIG. 6.

In order to realize thinning, however, a resin molded type semiconductordevice of the prior art has a structure in which substantially only theface of a lead frame on which a semiconductor chip is mounted, i.e., theupper face of the lead frame is molded by a sealing resin. Even when atapered shape is formed in an inner lead portion, therefore, the contactarea between the lead frame and the sealing resin is reduced as a whole,thereby producing a problem in that the adhesiveness is impaired and thereliability of a product is lowered. Since such a device has a structurein which substantially only the single face of the lead frame isresin-molded, there are further problems in that the semiconductor chipis adversely affected by stress of the sealing resin, and that packagecrack occurs in the sealing resin. When the inner lead portions areconnected to the semiconductor chip by thin metal wires and single-sidemolding is performed, there arises a further problem in that, because ofstress in the single-side molding structure, a load due to the stressacts on the inner lead portions which are connected by thin metal wires,and the connecting portions are broken, with the result that aconnection failure occurs.

Therefore, it is an object of the invention to provide a resin moldedtype semiconductor device which solves the above-discussed problems ofthe prior art, in which the adhesiveness between a lead frame and asealing resin is maintained and stable connection between thin metalwires and inner lead portions are enabled, which has high reliability,and in which thinning is realized, and a method of manufacturing thesemiconductor device.

DISCLOSURE OF INVENTION

In order to attain the object, the resin molded type semiconductordevice of the invention comprises: a semiconductor chip which is mountedon a die pad portion of a lead frame; thin metal wires whichelectrically connect terminals of an upper face of the semiconductorchip to inner lead portions of the lead frame; a sealing resin whichseals an outer peripheral region of the semiconductor chip, the regionincluding a thin metal wire region of the upper face of thesemiconductor chip, and a lower region of the die pad portion; and outerlead portions which are arranged in a bottom face region of the sealingresin, and is characterized in that the lead frame is subjected to anupsetting process so that the die pad portion is located at a positionhigher than the inner lead portions.

In this way, the lead frame is subjected to an upsetting process so thatthe die pad portion is located at a position higher than the inner leadportions. Therefore, the sealing resin of a thickness corresponding tothe step difference of the upsetting exists below the die pad portion,the adhesiveness between the lead frame and the sealing resin can beimproved, and the reliability of a product can be maintained. Even whenboth the faces, or the upper and lower faces of the lead frame areresin-molded, the thickness of the resin of the lower face is equal to avalue corresponding to the step difference of the upsetting.Consequently, the thinning can be realized.

Furthermore, the resin molded type semiconductor device of the inventioncomprises: a semiconductor chip which is mounted on a die pad portion ofa lead frame; thin metal wires which electrically connect terminals ofan upper face of the semiconductor chip to inner lead portions of thelead frame; a sealing resin which seals an outer peripheral region ofthe semiconductor chip, the region including a thin metal wire region ofthe upper face of the semiconductor chip; and outer lead portions whichare arranged in a bottom face region of the sealing resin and which areformed to be continuous to the respective inner lead portions, whereinat least one groove portion is formed in a surface of each of the innerlead portions.

In this way, at least one groove portion is formed in the surface ofeach of the inner lead portions. Therefore, the anchoring effect to thesealing resin can be improved, stress acting on a lead portion of aproduct, and stress to the thin metal wires can be relaxed, and leadsand the thin metal wires can be prevented from peeling off.Consequently, the reliability of a product can be maintained.

Furthermore, the resin molded type semiconductor device of the inventioncomprises: a semiconductor chip which is mounted on a die pad portion ofa lead frame; thin metal wires which electrically connect terminals ofan upper face of the semiconductor chip to inner lead portions of thelead frame; a sealing resin which seals an outer peripheral region ofthe semiconductor chip, the region including a thin metal wire region ofthe upper face of the semiconductor chip; and outer lead portions whichare arranged in a bottom face region of the sealing resin and which areformed to be continuous to the respective inner lead portions, and ischaracterized in that a plurality of groove portions are formed in asurface of each of the inner lead portions, and a connecting portion ofthe thin metal wire on a side of the inner lead portion is disposedbetween the groove portions.

In this way, a plurality of groove portions are formed in the surface ofeach of the inner lead portions, and a connecting portion of the thinmetal wire on the side of the inner lead portion is disposed between thegroove portions. Therefore, the anchoring effect to the sealing resincan be improved, stress acting on a lead portion of a product, andstress to the thin metal wires can be relaxed, and leads and the thinmetal wires can be prevented from peeling off. In this case, stress dueto the structure in which the single face of the lead frame is molded bythe sealing resin is absorbed by the groove portions, and does not acton an area between the groove portions. Therefore, the connectingportions of the thin metal wires are not broken and stable connection isenabled.

Furthermore, the resin molded type semiconductor device of the inventioncomprises: a semiconductor chip which is mounted on a die pad portion ofa lead frame; thin metal wires which electrically connect terminals ofan upper face of the semiconductor chip to inner lead portions of thelead frame; a sealing resin which seals an outer peripheral region ofthe semiconductor chip, the region including a thin metal wire region ofthe upper face of the semiconductor chip; and outer lead portions whichare arranged in a bottom face region of the sealing resin and which areformed to be continuous to the respective inner lead portions, and ischaracterized in that a widened portion is formed in each of the innerlead portions.

In this way, a widened portion is formed in the inner lead portions.Therefore, the anchoring effect to the sealing resin can be improved,stress acting on a lead portion of a product, and stress to the thinmetal wires can be relaxed, and leads and the thin metal wires can beprevented from peeling off. Consequently, the reliability of a productcan be maintained.

Furthermore, the resin molded type semiconductor device of the inventioncomprises: a semiconductor chip which is mounted on a die pad portion ofa lead frame; thin metal wires which electrically connect terminals ofan upper face of the semiconductor chip to inner lead portions of thelead frame; a sealing resin which seals an outer peripheral region ofthe semiconductor chip, the region including a thin metal wire region ofthe upper face of the semiconductor chip; and outer lead portions whichare arranged in a bottom face region of the sealing resin and which areformed to be continuous to the respective inner lead portions, and ischaracterized in that a widened portion is formed in each of the innerlead portions and at least one groove portion is formed in a surface.

In this way, a widened portion is formed in each of the inner leadportions and at least one groove portion is formed in the surface.Therefore, the anchoring effect to the sealing resin can be furtherimproved, stress acting on a lead portion of a product, and stress tothe thin metal wires can be further relaxed, and the effect ofpreventing leads and the thin metal wires from peeling off is enhanced.

Furthermore, the resin molded type semiconductor device of the inventioncomprises: a semiconductor chip which is mounted on a die pad portion ofa lead frame; thin metal wires which electrically connect terminals ofan upper face of the semiconductor chip to inner lead portions of thelead frame; a sealing resin which seals an outer peripheral region ofthe semiconductor chip, the region including a thin metal wire region ofthe upper face of the semiconductor chip; and outer lead portions whichare arranged in a bottom face region of the sealing resin and which areformed to be continuous to each of the inner lead portions, and ischaracterized in that a widened portion is formed in each of the innerlead portions, a plurality of groove portions are formed in a surface,and connecting portions of the thin metal wires on a side of the innerlead portion are disposed between the groove portions.

In this way, a widened portion is formed in each of the inner leadportions, a plurality of groove portions are formed in the surface, andconnecting portions of the thin metal wires on a side of the inner leadportion are disposed between the groove portions. Therefore, theanchoring effect to the sealing resin can be further improved, stressacting on a lead portion of a product, and stress to the thin metalwires can be further relaxed, and the effect of preventing leads and thethin metal wires from peeling off is enhanced. In this case, when two ormore groove portions are disposed and the thin metal wires are connectedto an area between the groove portions, the effect of absorbing stresscan be enhanced. Moreover, stress due to the structure in which thesingle face of the lead frame is molded by the sealing resin is absorbedby the groove portions, and does not act on an area between the grooveportions. Therefore, the connecting portions of the thin metal wires arenot broken and stable connection is enabled.

According to the resin molded type semiconductor device of theinvention, in the above configuration, exposed faces of the outer leadportions are arranged in a same level as an outer face of the sealingresin. In this way, the exposed faces of the outer lead portions arearranged in the same level as the outer face of the sealing resin.Unlike the prior art, therefore, the outer lead portions can be arrangedso as to be embedded in the bottom face portion of the sealing resin,while the outer lead portions project from a side face of the sealingresin. Therefore, the reliability of the outer lead portions serving asexternal terminals can be improved, and it is possible to provide aresin molded type semiconductor device which is miniaturized by a sizecorresponding to the nonprojecting structure of the outer lead portions.

Furthermore, the method of manufacturing a resin molded typesemiconductor device of the invention comprises the steps of: performingan upsetting process on a lead frame so that a die pad portion islocated at a position higher than inner lead portions; bonding asemiconductor chip to the die pad portion of the lead frame;electrically connecting terminals of the semiconductor chip to the innerlead portions of the lead frame by thin metal wires; sealing an outerperipheral region of the semiconductor chip, thereby forming a sealingresin, the region including a region of an upper face of thesemiconductor chip and electrically connected by the thin metal wires,and a lower region of the die pad portion; and shaping outer leadportions of the lead frame so as to be exposed from an outer face of thesealing resin.

In this way, the lead frame is subjected to an upsetting process so thatthe die pad portion is located at a position higher than the inner leadportions, and the outer peripheral region of the semiconductor chipincluding the region of the upper face of the semiconductor chip andelectrically connected by the thin metal wires, and the lower region ofthe die pad portion is molded to form the sealing resin. Therefore, thesealing resin of a thickness corresponding to the step difference of theupsetting exists below the die pad portion, the adhesiveness between thelead frame and the sealing resin can be improved, and the reliability ofa product can be maintained. Even when both the faces, or the upper andlower faces of the lead frame are resin-molded, the thickness of theresin of the lower face is equal to the thickness of the step differenceof the upsetting. Consequently, the thinning can be realized.

Furthermore, the method of manufacturing a resin molded typesemiconductor device of the invention is characterized in that themethod comprises the steps of: bonding a semiconductor chip to a leadframe having inner lead portions in each of which a widened portion isdisposed and at least one groove portion is formed in a surface;electrically connecting terminals of the semiconductor chip to the innerlead portions of the lead frame by thin metal wires; sealing an outerperipheral region of the semiconductor chip, thereby forming a sealingresin, the region including a region of an upper face of thesemiconductor chip and electrically connected by the thin metal wires,and a lower region of the semiconductor chip; and shaping outer leadportions of the lead frame so as to be exposed from an outer face of thesealing resin, and, when the terminals of the semiconductor chip are tobe electrically connected to the inner lead portions by the thin metalwires, the connection is performed while connecting portions of the thinmetal wires on the side of the inner lead portions are disposed in thevicinity of the groove portion.

In this way, when the terminals of the semiconductor chip are to beelectrically connected to the inner lead portions by the thin metalwires, the connection is performed while connecting portions of the thinmetal wires on the side of the inner lead portions are disposed in thevicinity of the groove portion. Therefore, stress due to the structurein which the single face of the lead frame is molded by the sealingresin is absorbed by the groove portion, the connecting portions of thethin metal wires are not broken, and stable connection is enabled.Moreover, the anchoring effect to the sealing resin can be improved, andstress acting on a lead portion of a product can be relaxed by thegroove portion, and leads and the thin metal wires can be prevented frompeeling off.

Furthermore, the method of manufacturing a resin molded typesemiconductor device of the invention is characterized in that themethod comprises the steps of: bonding a semiconductor chip to a leadframe having inner lead portions in each of which a widened portion isdisposed and a plurality of groove portions are formed in a surface;electrically connecting terminals of the semiconductor chip to the innerlead portions of the lead frame by thin metal wires; sealing an outerperipheral region of the semiconductor chip, thereby forming a sealingresin, the region including a region of an upper face of thesemiconductor chip and electrically connected by the thin metal wires,and a lower region of the semiconductor chip; and shaping outer leadportions of the lead frame so as to be exposed from an outer face of thesealing resin, and, when the terminals of the semiconductor chip are tobe electrically connected to the inner lead portions by the thin metalwires, the connection is performed while connecting portions of the thinmetal wires on the side of the inner lead portions are disposed betweenthe groove portions.

In this way, when the terminals of the semiconductor chip are to beelectrically connected to the inner lead portions by the thin metalwires, the connection is performed while connecting portions of the thinmetal wires on the side of the inner lead portions are disposed betweenthe groove portions. Therefore, stress due to the structure in which thesingle face of the lead frame is molded by the sealing resin is absorbedby the groove portions, and does not act on an area between the grooveportions. Consequently, the connecting portions of the thin metal wiresare not broken, and stable connection is enabled. In this case, when twoor more groove portions are disposed and the thin metal wires areconnected to an area between the groove portions, the effect ofabsorbing stress can be enhanced. Moreover, the anchoring effect to thesealing resin can be further improved, and stress acting on a leadportion of a product can be further relaxed by the plural grooveportions, and the effect of preventing leads and the thin metal wiresfrom peeling off is enhanced.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a section view shoving a resin molded type semiconductordevice of an embodiment of the invention,

FIG. 1A illustrates the resin contacting the bottom of the chip,

FIG. 2 is a plan view showing the resin molded type semiconductor deviceof the embodiment of the invention,

FIG. 3 is an enlarged section view of main portions of the resin moldedtype semiconductor device of the embodiment of the invention,

FIG. 4(a) is a plan view of an inner lead portion of the resin moldedtype semiconductor device of the embodiment of the invention,

FIG. 4(b) is a left side view,

FIG. 4(c) is a front view,

FIG. 5 is a section view of a resin molded type semiconductor device ofthe prior art, and

FIG. 6 is a section view showing another example of a resin molded typesemiconductor device of the prior art.

BEST MODE FOR CARRYING OUT THE INVENTION

A resin molded type semiconductor device of an embodiment of theinvention will be described with reference to FIGS. 1 to 4.

FIG. 1 is a section view of the resin molded type semiconductor deviceof the embodiment of the invention, FIG. 2 is a plan view of the device,FIG. 3 is an enlarged section view showing an inner lead portion of thedevice, FIG. 4(a) is an enlarged plan view showing a tip end of theinner lead portion, FIG. 4(b) is a left side view, and FIG. 4(c) is afront view. In FIG. 2, for the sake of convenience, the plan view is aview which is obtained by partially removing away a sealing resin, inorder to show the internal structure. In the figure, broken lines show adie pad portion and part of suspension leads.

As shown in FIGS. 1 and 2, the resin molded type semiconductor devicecomprises: a semiconductor chip 12 which is mounted on a die pad portion11 of a lead frame 9 and serving as a supporting portion of thesemiconductor chip 12 supported by suspension leads 10; thin metal wires14 which electrically connect terminals of the upper face of thesemiconductor chip 12 to inner lead portions 13 of the lead frame 9; asealing resin 15 which seals an outer peripheral region of thesemiconductor chip 12 including a thin metal wire 14 region of the upperface of the semiconductor chip 12, and a lower region of the die padportion 11; and outer lead portions 16 which are arranged in a bottomface region of the sealing resin 15, which are formed to be continuousto the respective inner lead portions 13, and which serve as externalterminals. The lead frame 9 is subjected to an upsetting process so thatthe die pad portion 11 is located at a position higher than the innerlead portions 13. In the embodiment, the device is configured so thatthe die pad portion 11 is smaller in area than the semiconductor chip 12to be mounted. As described above, in the resin molded typesemiconductor device, the suspension leads 10 are subjected to anupsetting process, and a step portion 17 is provided. Therefore, asealing resin 15 a can exist also below the die pad portion 11. Althoughthe device is of the thin type, the device is a semiconductor devicewhich is substantially of the double-side molding type with respect tothe lead frame 9.

FIG. 1A shows chip 12 wider than die pad portion 11, with the resin 15thus contacting the bottom of the chip. As noted below, there is contactthrough adhesiveness between the resin and the rear face of chip 12.

As shown in FIGS. 3 and 4, each of the inner lead portions 13 has awidened portion 18 at a tip end portion, and a plurality of grooveportions 19 are formed in the surface. In the end face of the tip endportion of the inner lead portion 13, a reverse taper is formed in thethickness direction. The outer lead portions 16 are arranged so thattheir exposed faces are in a substantially same level as a side faceportion of the sealing resin 15, and do not protrude from the sealingresin 15 unlike the prior art configuration. Therefore, deformation ofthe outer lead portions 16, and the like can be prevented fromoccurring, and the device is a semiconductor device of the surface mounttype. Moreover, the connecting portion of each thin metal wire 14 on theside of the inner lead portion 13 are disposed between the grooveportions 19.

The resin molded type semiconductor device of the embodiment is a resinmolded type semiconductor device which is very thin or has a totalthickness of 0.7 [mm], and has a target thickness which is not largerthan a sum of the thickness of a semiconductor chip and 1 [mm]. The stepdifference of the upsetting process of the suspension leads 10 is 0.1[mm], and the thickness of the sealing resin 15 a below the die padportion 11 is 0.1 [mm]. The thickness of the semiconductor chip 12 is0.2 [mm], and a sealing resin 15 b above the die pad portion 11 is 0.15[mm].

Next, a method of manufacturing the resin molded type semiconductordevice of the embodiment shown in FIGS. 1 to 4 will be described.

First, the suspension leads 10 supporting the die pad portion 11 of thelead frame 9 is pressurized to be subjected to an upsetting process,thereby forming the step portion 17. The semiconductor chip 12 is bondedat the bottom face side to the die pad portion 11 of the lead frame 9 byan electrically conductive adhesive agent.

Next, the terminals of the semiconductor chip 12 on the die pad portion11 are electrically connected to the inner lead portions 13 of the leadframe 9 by the thin metal wires 14. At this time, each thin metal wire14 which is to be connected to the side of the corresponding inner leadportion 13 is connected so as to exist between two groove portions 19which are disposed in the surface of the inner lead portion 13.

Next, the outer peripheral region of the semiconductor chip 12 is moldedby the sealing resin 15 by means of transfer molding. In this case, theupper face of the semiconductor chip 12, i.e., the region whereelectrical connection is done by the thin metal wires 14, and the lowerregion of the die pad portion 11 are molded, thereby forming the sealingresin 15 a and the sealing resin 15 b. The thickness of the sealing bythe sealing resin 15 is set so that the sealing resin 15 a below the diepad portion 11 is flush with the bottom face of the inner lead portion13 and the sealing resin 15 b on the upper face of the semiconductorchip 12 has a thickness which is larger than the loop height of the thinmetal wires 14. In the resin sealing step, the sealing must be performedso as to attain excellent air tightness so that the sealing resin 15does not enter the bottom region of the inner lead portions 13.

Then, the outer lead portions 16 of the lead frame 9 are shaped so as tobe exposed with being flush with the outer face of the sealing resin 15.

As a result of the above-described steps, it is possible to realize aresin molded type semiconductor device of the double-side molding typewith respect to the lead frame 9. Because of the double-side moldingstructure, the adhesiveness between the sealing resin 15 and the leadframe 9 is ensured, and package crack is prevented from occurring,thereby enabling the reliability to be maintained.

Furthermore, by the widened portion 18 and the groove portions 19 whichare disposed in the surface of each of the inner lead portions 13, theadhesiveness with the sealing resin 15 can be improved, and stress whichacts on the inner lead portions 13 and due to the single-side moldingstructure can be relaxed, and also the adhesiveness (anchoring effect)with the sealing resin 15 can be improved. In other words, dislocationfrom the sealing resin 15 to the inner lead portions 13 is preventedfrom occurring.

With respect to the inner lead portions 13, the sealing resin 15 isformed into the single-side molding structure. According to thisstructure, therefore, stress by the sealing resin 15 acts on the innerlead portions 13. However, the groove portions 19 are formed in theinner lead portions 13, and the stress acting on the inner lead portions13 can be absorbed by the groove portions 19 so as to be relaxed. Sincethe connecting portions are disposed between the groove portions 19, theconnecting portions are not damaged by the stress to be broken.

As described above, according to the embodiment, the suspension leads 10of the lead frame 9 are subjected to the upsetting process, and the diepad portion 11 is raised to a level higher than the inner lead portions13. Therefore, the sealing resin 15 of a thickness corresponding to thestep difference of the upsetting exists below the die pad portion 11,the adhesiveness between the lead frame 9 and the sealing resin 15 canbe improved, and the reliability of a product can be maintained. Unlikethe prior art, the outer lead portions 16 are arranged so as to beembedded into the bottom face portion of the sealing resin 15 withoutprojecting from the side face of the sealing resin 15. Therefore, thereliability of the outer lead portions serving as external terminals canbe improved, and it is possible to provide a resin molded typesemiconductor device which is miniaturized by a size corresponding tothe nonprojecting structure of the outer lead portions. Even when boththe faces, or the upper and lower faces of the lead frame 9 areresin-molded, the thickness of the resin of the lower face is equal tothe thickness of the step difference of the upsetting. Consequently, thethinning can be realized.

Furthermore, the reduction of the area of the die pad portion 11, andthe disposition of an opening can enhance the adhesiveness between thesealing resin 15 and the rear face of the semiconductor chip 12, and thereliability can be ensured.

Furthermore, the adhesiveness with the sealing resin can be improved,and stress which acts on the inner lead portions 13 and due to thesingle-side molding structure can be relaxed by the widened portion 18and the groove portions 19 which are disposed in the surface of each ofthe inner lead portions 13. Particularly, the groove portions 19 absorbstress to the connecting portions of the thin metal wires 14 on the sideof the inner lead portions 13. Therefore, the connecting portions of thethin metal wires 14 are not affected by stress, breakage of theconnecting portions is prevented from occurring, stable connection isenabled, and the reliability of a product can be improved, whereby thereliability of the resin molded type semiconductor device can beimproved.

In the embodiment, the number of the groove portions 19 of each of theinner lead portions 13 is two. Alternatively, a single groove portionmay be disposed and the thin metal wire may be connected to the vicinityof the groove portion, whereby stress acting on the inner lead portion13 and that on the thin metal wire can be relaxed. Alternatively, two ormore groove portions may be formed, and the thin metal wire may beconnected to an area between the groove portions, whereby the effect ofabsorbing stress can be enhanced. The groove direction of the grooveportions elongates along a side face of the semiconductor device.Alternatively, the groove direction may be set to be any direction suchas that which intersects a side face. The groove portions may be formedinto a mesh-like shape in which grooves elongate longitudinally andlatitudinally. Both the groove portions and the widened portion aredisposed. Alternatively, only one of the two kinds of portions may bedisposed.

1. A resin molded type semiconductor device comprising: a semiconductorchip which is mounted on a die pad of a lead frame; thin metal wireswhich electrically connect terminals of an upper face of saidsemiconductor chip to inner lead portions of said lead frame; a sealingresin which seals an outer peripheral region of said semiconductor chip,said region including a thin metal wire region of the upper face of saidsemiconductor chip; and outer lead portions which are arranged in abottom face region of said sealing resin and which are formed to becontinuous to respective inner lead portions, wherein at least onegroove portion is formed in a surface of each of said inner leadportions, a connecting portion of each of said thin metal wires iscoupled to a respective inner lead portion at a flat surface region ofsaid respective inner lead portion adjacent said at least one grooveportion.
 2. A resin molded type semiconductor device according to claim1, wherein exposed faces of said outer lead portion are arranged in asame level as an outer face of said sealing resin.
 3. A resin moldedtype semiconductor device comprising: a die pad; and leads includinginner lead portions and outer lead portions, each of said inner leadportions including at least one groove portion which is formed in asurface thereof; a semiconductor chip mounted over said die pad; thinmetal wires which electrically connect terminals of said semiconductorchip to said inner lead portions at a position not on said grooveportion; and a sealing resin which seals said groove portion, an outerperipheral region of said semiconductor chip, an entire upper region ofsaid inner lead portions and parts of said inner lead portions whoresaid thin metal wires are electrically connected, said outer peripheralregion including a region of said thin metal wires, wherein said sealingresin leaves an entire bottom surface of said inner lead portionsunsealed.
 4. The resin molded type semiconductor device according toclaim 3, wherein each of said inner lead portions includes said at leastone groove portion which is formed in an upper surface of said innerlead portions.
 5. The rosin molded semiconductor device according toclaim 4, wherein said die pad is disposed higher than said upper surfaceof said inner lead portions, and said sealing resin seals a lower regionof said die pad.
 6. The resin molded type semiconductor device accordingto claim 5, wherein a bottom surface of said die pad is disposed higherthan a bottom surface of said inner lead portions.
 7. The resin moldedtype semiconductor device according to claim 6, wherein at least aportion of said outer periphery of said semiconductor chip extendsoutward from said outer periphery of said die pad.
 8. The resin moldedtype semiconductor device according to claim 7, wherein said grooveportion absorbs stress at a connection between said thin metal wires andsaid inner lead portions.
 9. A resin molded type semiconductor deviceaccording to claim 8, wherein a total thickness is not greater than asum of a thickness of said semiconductor chip and 1 mm.
 10. The resinmolded type semiconductor device according to claim 8, wherein exposedfaces of said outer lead portions are substantially arranged in a sameplane as an outer surface of said sealing resin.
 11. A resin molded typesemiconductor device comprising: a die pad; and leads each including atleast one groove portion which is formed in a surface thereof; asemiconductor chip mounted over said die pad; thin metal wires whichelectrically connect terminals of said semiconductor chip to said leadsat a position not on said groove portion; and a sealing resin whichseals said groove portion, said thin metal wires, said semiconductorchip, an upper region of said leads and parts of said leads where saidthin metal wires are electrically connected, wherein said sealing resinleaves an entire bottom surface of said leads unsealed.
 12. The resinmolded type semiconductor device according to claim 11, wherein each ofsaid leads includes said at least one groove portion which is formed inan upper surface of said leads.
 13. The resin molded type semiconductordevice according to claim 12, wherein said die pad is disposed higherthan said upper surface of said leads.
 14. The resin molded typesemiconductor device according to claim 13, wherein a bottom surface ofsaid die pad is disposed higher than a bottom surface of said leads. 15.The resin molded type semiconductor device according to claim 14,wherein at least a portion of said outer periphery of said semiconductorchip extends outward from said outer periphery of said die pad.
 16. Theresin molded type semiconductor device according to claim 15, whereinsaid groove portion absorbs stress at a connection between said thinmetal wires and said leads.
 17. A resin molded type semiconductor deviceaccording to claim 16, wherein a total thickness is not greater than asum of a thickness of said semiconductor chip and 1 mm.
 18. The resinmolded type semiconductor device according to claim 8, wherein exposedfaces of said leads are substantially arranged in a same plane as anouter surface of said sealing resin.
 19. A resin molded typesemiconductor device comprising a die pad; leads including inner leadportions and outer lead portions, each of said inner lead portionsincluding at least one groove portion which is formed in a surfacethereof; a semiconductor chip mounted over said die pad; thin metalwires which electrically connect terminals of said semiconductor chip tosaid inner lead portions at a position not on said groove portion; and asealing resin which seals said groove portion, an outer peripheralregion of said semiconductor chip, the entire top surface of said innerlead portions and parts of said inner lead portions where said thinmetal wires are electrically connected, said outer peripheral regionincluding a region of said thin metal wires, wherein said sealing resinleaves unsealed at least the bottom surface of a part of said inner leadportions where said groove portion is formed.
 20. The resin molded typesemiconductor device according to claim 19, wherein each of said innerlead portions includes said at least one groove portion which is formedin an upper surface of said inner lead portions.
 21. The resin moldedtype semiconductor device according to claim 20, wherein said die pad isdisposed higher than said upper surface of said inner lead portions, andsaid sealing resin seals a lower region of said die pad.
 22. The resinmolded type semiconductor device according to claim 21, wherein a bottomsurface of said die pad is disposed higher than a bottom surface of saidinner lead portions.
 23. The resin molded type semiconductor deviceaccording to claim 22, wherein at least a portion of said outerperiphery of said semiconductor chip extends outward from said outerperiphery of said die pad.
 24. The resin molded type semiconductordevice according to claim 23, wherein said groove portion absorbs stressat a connection between said thin metal wires and said inner leadportions.
 25. A resin molded type semiconductor device according toclaim 24, wherein a total thickness is not greater than a sum of athickness of said semiconductor chip and 1 mm.
 26. The resin molded typesemiconductor device according to claim 24, wherein exposed faces ofsaid outer lead portions are substantially arranged in a same plane asan outer surface of said sealing resin.
 27. A resin molded typesemiconductor device comprising: a die pad; lead each including at leastone groove portion which is formed in a surface thereof; a semiconductorchip mounted over said die pad; thin metal wires which electricallyconnect terminals of said semiconductor chip to said leads at a positionnot on said groove portion; and a sealing resin which seals said grooveportion, said thin metal wires, said semiconductor chip, a top surfaceof said leads and parts of said leads where said thin metal wires areelectrically connected, wherein said sealing resin leaves unsealed atleast the bottom surface of a part of said leads where said grooveportion is formed.
 28. The resin molded type semiconductor deviceaccording to claim 27, wherein each of said leads includes said at leastone groove portion which is formed in an upper surface of said leads.29. The resin molded type semiconductor device according to claim 28,wherein said die pad is disposed higher than said upper surface of saidleads.
 30. The rosin molded type semiconductor device according to claim29, wherein a bottom surface of said die pad is disposed higher than abottom surface of said leads.
 31. The resin molded type semiconductordevice according to claim 30, wherein at least a portion of said outerperiphery of said semiconductor chip extends outward from said outerperiphery of said die pad.
 32. The resin molded type semiconductordevice according to claim 31, wherein said groove portion absorbs stressat a connection between said thin metal wires and said leads.
 33. Aresin molded type semiconductor device according to claim 32, wherein atotal thickness is not greater than a sum of a thickness of saidsemiconductor chip and 1 mm.
 34. The resin molded type semiconductordevice according to claim 32, wherein exposed faces of said leads aresubstantially arranged in a same plane as an outer surface of saidsealing resin.